1. Field of the Invention
The present invention relates to a character or letter segmentation technique in an optical character read-out device and, particularly, to a character or letter segmentation technique for segmenting out a character or letter in contact with an adjacent character or letter.
2. Description of Related Art
The character or letter segmentation technique is used in an optical character reader to segmentation out a character or letter to be sensed from an electronic picture obtained by For example; optical scanning. In this description, the term "character" means either a character or a letter. An example of the conventional character segmentation system is disclosed in Japanese Patent Application Laid-open No. Hei 8-129611. In the disclosed character segmentation system, a pattern of a specific character is preliminary registered as a reference character and the specific character is sensed by obtaining a correlation between the reference character and a string of characters which are in contact with the specific character.
An example of the conventional character segmentation position detecting system is disclosed in Japanese Patent Application Laid-open No. Hei 5-307640. According to the disclosed conventional character segmentation position detecting system, a picture is stored as monochromatic values and the confidence of character segmentation is improved by changing a binary threshold value according to the kind or font of character.
The conventional system disclosed in Japanese Patent Application Laid-open No. Hei 8-129611 is effective if the number of fonts of character is small. However, it has such problems as that, when a number of character fonts are to be read out, the registration work for the character patterns of the reference characters is troublesome and that the size of mechanism for storing the reference characters becomes large.
Further, since it is necessary in the character segmentation position detecting system disclosed in Japanese Patent Application Laid-open No. Hei 5-307640 to store a picture as monochromatic values, there is a problem that considerable resources such as memories are required.
Further, there is another problem in the conventional character segmentation method that the character segmentation tends to be influenced by variation of the touching case of characters due to the difference in font between characters.